This application discloses and claims a self-contained refrigeration unit that is designed to be installed in suitable receiving recesses in a truck or trailer refrigeration body. The refrigeration unit can be mounted entirely with a removable casing such that only electrical connections need be removed or attached to replace the unit, or in one embodiment some minor refrigerant connections may also need to be completed.
So-called refrigeration trucks have a trailer or compartments that are cooled or refrigerated to preserve cargo, such as food stuffs. Typically, the various components of a refrigerant cycle are mounted into the truck separately and apart from each other. As a consequence of this configuration, a significant amount of tubing and electrical wiring is used to control and route the refrigerant between the components of the refrigeration system. This tubing and wiring prevents the easy installation and removal of these components, requiring significant labor and expense to connect and disconnect the components of the refrigeration system for installation or maintenance.
For example, repair of the evaporator requires the disconnection of the evaporator from the truck trailer""s refrigeration system and then removal of this particular component. While this component is repaired, the refrigeration system is rendered useless and the truck inoperable for refrigeration during the time of repair.
Also, refrigerated trucks typically have the refrigerant circuit mounted in a box above the nominal top of the vehicle cabin. Space in this area tends to be crowded as a consequence of increased space for the driver.
A need therefore exists for a refrigeration system that can be easily repaired without causing significant downtime in the use of the refrigeration truck.
The present invention comprises a self-contained refrigeration unit that permits convenient installation and removal of the unit from a vehicle. Like existing refrigeration systems, the refrigeration unit comprises an evaporator, a condenser and a compressor. In contrast to such systems, however, the refrigeration unit localizes these refrigeration components on a casing of a standardized size to support the evaporator, condenser and compressor. This casing is tailored to fit a frame having an opening of about the same standardized size to receive the casing. The frame is part of the vehicle refrigeration compartment. Insulation is also provided between refrigeration components within the unit so as to promote their efficient operation. The entire refrigeration unit may be quickly and easily installed and removed from the vehicle as a modular unit by simply moving the casing in and out of the frame.
In one preferred embodiment, the refrigerant flow of the refrigeration unit is entirely self-contained within the casing. In this configuration, the refrigeration unit may be installed without connecting refrigeration tubing to the unit and may be removed without disconnecting such tubing. To facilitate quick and easy installation and removal, the refrigeration unit also employs a power connector on the casing and a matching power connector about the frame of the vehicle so that the refrigeration unit may be quickly powered by plugging the connectors together. Also, the casing may have a control connector on the casing with a matching control connector on the frame. Thus, the entire refrigeration unit may be conveniently installed and removed on the vehicle without spending significant time making connections to operate the refrigeration unit.
The unit may be placed in the roof of the vehicle compartment. The unit may also be placed on the walls of the compartment. It is also preferable that a seal be employed between the casing and the frame to insulate the vehicle compartment from ambient temperatures. A layer of the installation between the evaporator and condenser is also used.
In a second embodiment, the compressor is powered by a power take off from the vehicle drive. In this embodiment, a simple check valve connection is placed on the casing such that the refrigerant may be routed to and from the compressor. The invention still facilitates the changing of the refrigeration unit should the evaporator or condenser fail.
The modular nature of the refrigeration unit permits a number of units to be installed on a vehicle on one or multiple trailers. Each of these units may be controlled individually or separately by a control unit. A multiplex bus communication system may be employed to control each unit.
The present invention also permits the storing of an inventory of refrigeration units all of about the same standard size. Accordingly, rather than repair a refrigeration unit on the vehicle, the malfunctioning refrigeration unit may be quickly and easily removed and replaced with another standardized refrigeration unit from inventory. The refrigeration unit may then be repaired without causing significant down time to the operation of the vehicle.